Abstract
The aim of this paper is to offer a rigorous explication of statements ascribing ability to agents and to develop the logic of such statements. A world is said to be feasible iff it is compatible with the actual past-and-present. W is a P-world iff W is feasible and P is true in W (where P is a proposition). P is a sufficient condition for Q iff every P world is a Q world. P is a necessary condition for Q iff Q is a sufficient condition forP. Each individual property S is shown to generate a rule for an agent X. X heeds S iff X makes all his future choices in accordance with S. (Note that X may heed S and yet fail to have it). S is a P-strategy for X iff X's heeding S together with P is a necessary and sufficient condition for X to have S. (P-strategies are thus rules which X is able to implement on the proviso P).Provisional opportunity: X has the opportunity to A provided P iff there is an S such that S is a P-strategy for X and X's implementing S is a sufficient condition for X's doing A. P is etiologically complete iff for every event E which P reports P also reports an etiological ancestry of E, and P is true. Categorical opportunity: X has the opportunity to A iff there is a P such that P is etiologically complete and X has the opportunity to A provided P. For X to have the ability to A there must not only be an appropriate strategy, but X must have a command of that strategy. X steadfastly intends A iff X intends A at every future moment at which his doing A is not yet inevitable. X has a command of S w.r.t. A and P iff X's steadfastly intending A together with P is a sufficient condition for X to implement S. Provisional ability: X can A provided P iff there is an S such that S is a P-strategy for X, X's implementing S is a sufficient condition for X's doing A, and X has a command of S w.r.t. A and P. Categorical ability: X can A iff there is a P such that P is etiologically complete and X can A provided P. X is free w.r.t. to A iff X can A and X can non- A. X is free iff there is an A such that X is free w.r.t. A.
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References
P. Tichý, A new theory of subjunctive conditionals, Synthese 37 (1978), pp. 433–457.
P. Tichý, The logic of temporal discourse, Lingusitics and Philosophy 3 (1980), pp. 393–369.
P. Tichý, The semantics of episodic verbs, Theoretical Linguistics 7 (1980), pp. 263–296.
P. Tichý, Foundations of partial type theory, Reports on Mathematical Logic 14 (forthcoming).
P. Tichý and G. J. Oddie, Ability and Freedom, The American Philosophical Quarterly (forthcoming).
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Oddie, G., Tichý, P. The logic of ability, freedom and responsibility. Stud Logica 41, 227–248 (1982). https://doi.org/10.1007/BF00370346
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DOI: https://doi.org/10.1007/BF00370346